Centrifugal unloader for compressors



F. W. PARSONS CENTRIFUGAL UNLOADER FOR COMPRESSORS May 8, 1923.

3 Sheets-Sheet 1 Filed May 29, 1922 INVENTOR fieaerjc/Y )1. Parsons Hi5 ATTORN May 8, 1923. I 11,454,402

F. w. PARSONS CENTRIFUGAL UNLOADER FOR COMPRESSORS Filad May 29, 1922 3 smu -sham H15 ATTORNEY May-8, 19,23. 1,454,402 F. w. PARSONS 4 CBNTRIFUGAL UNLOADER FOR COMPRBSSORS I Filed May 29, 1922 :5 shuts-shut 5 guvemCo-z flea erzkkmraoua Patented May 8, 1923.

. 1,454,402 PTENT oFFicE.

FREDERICK W. PARSONS, OF ELMIRA, NEW YORK, ASSIGNOR T0 INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

CENTRIFUGAL UNLOADER FOR COMPRESSORS.

Application filed May 29, 1922. Serial No. 564,459.

To all whom it may concern:

Be it known that I, FREDERICK W. PAR- SONS, a citizen of the United States, and a resident of Elmira, county of Chemung, and State of New York, have invented a certain Centrifugal Unloader for Compressors, of which the following is a specification accompanied by drawings.

This invention relates to compressors, but more particularly to a centrifugal unloading device, which maintains the inlet valve or valves open on starting, until the compressor has attained sufficient speed to cause the centrifugal device to act and through suitable leverage devices, release the inlet valve or valves so that it or they may function normally.

The objects of the invention are to improve upon and simplify the construction of such centrifugal unloaders, cheapen the cost of manufacture, secure a compact device which may readily be applied to a compressor, and enable the operative parts of the'automatic unloading device to be protected as much as possible.

' Further objects of the invention will here- 'inafter appear and to all of these ends the invention consists of the combinations of elements, arrangement of parts and features of construction, having the general mode of operation, substantally as hereinafter fully described and claimed in the specification, and shown in the accompanying drawings, in which i Figure 1 is a longitudinal sectional elevation of a compressor, having the invention applied thereto,

Figure 2 is a sectional elevation partly broken away of so much of the compressor as will serve to indicate the unloader in a different position from that shown in Figure 1.

Figure 3 is an enlarged detail transverse sectional view taken through the centrifugal device on the line 33 of Figure 1, looking in the direction of the arrows,

Figure 4 is a detail perspective view of one of the centrifugal weights, and

Figures 5 and 6 are sectional elevations partly broken away of a portion of the compressor having a modified form of the unloader applied thereto, the parts being shown in different positions in the two figures.

Referring to the drawings, a vertical compressor is shown for illustrating the invention, having the base A and the jacketed cylinder B, in which the piston C reciprocates. The cylinder is provided with a head I) having suitable inlet and discharge valves, 1n this lnstance, two inlet valves E being shown and the discharge valves not being iiidicated. The discharge pipe F is shown connected to the head D.

The piston C is connected to the crank G of the crank shaft H by the connecting rod J and the machine is driven from the pulley or fiy-wheel K in any suitable or usual manner. The oiling device L shown within the crank case forms no part of the present invention and will not be further described,

as it forms the subject matter of the copendon the pins R and S carried by the bracket.

T, which is suitably secured as by means of the screw U to the end of the crank shaft. A pin V extends outwardly from the crank shaft in an axial direction and a movable member in the form of a cap W is slidable upon the pin V. The centrifugal weights are provided with hooks or cam members X adapted to bear against the slidable cap W and force said .cap outwardly upon a sufficient increase of speed of the compressor, which will cause the weights to fly outwardly. I

Leverage devices, in the from of a lever Y and a bar Z pivoted thereto at a, extend for the same. The slidable cap W is adapted to bear against a plate e on the shield and forces said shield and the lower end of the lever outwardly, thus rocking the lever on its pivot 0 when the weights 0 and P fly outwardly a sufficient distance.

When the machine is at rest the bar Z as shown in Figure 1, lies over the inlet valve or valves E, holding them open because the bar Z is guided by the guide pins f. When the leverage devices are rocked to the position indicated in Figure 2, the openings g and'h in the bar Z are brought opposite the ends of the valves E so that said valves may function normallly.

A coiled spring carried on the adjustable clip is is adapted to be compressed against the compressor casing d as the lever Y is rocked. By moving the clip k to different positions along the lever Y, the resistance to the rocking of the lever Y is varied, thus affording means for adjusting and timing the operation of the centrifugal unloader.

In the modification shown in Figures 5 and 6, the sliding bar Z is omitted and the bracket 0 is suitably secured to the head 1) as by means of the screw p. A curved arm Q is pivoted to the bracket 0 at the point 1" and one end of the curved arm 9 is provided with a ring or loop 8 engaging the upper end of the lever Y. The other end t of the curved arm 9 is adapted to cooperate with the inlet valve E of which only one is shown in this instance. As the lever Y is rocked with sufficient increase of speed of the compressor, the curved arm q will also be rocked about its pivot from the position indicated in Figure 5 to that shown in Figure 6 thus releasing the inlet valve.

I claim:

1. In a compressor, the combination of a cylinder, piston and crank shaft, an inlet valve for the cylinder, centrifugal weights pivotally mounted on one end of the crank shaft, a slidable member actuated axially and outwardly from the crank shaft as the weights fly outwardly, a pivoted lever extending from a point near the inlet valve to a point opposite the weights. a shield on said lever extending over the weights and adapted to be engaged by said slidable member, means connected to the lever and bearing on the inlet valve for holding the inlet valve open on starting, said means acting to release the valve when the compressor has attained sufficient speed to cause the weights and slidable member to rock the said pivoted lever.

2. In a compressor, the combination of a cylinder, piston and crank shaft, an inlet valve for the cylinder, centrifugal weights pivotally mounted on one end of the crank shaft, a slidable member actuated axially and outwardly from the crank shaft as the weights fly outwardly, pivotally mounted leverage devices extending from the inlet valve to a point opposite the centrifugal weights in position to be rocked by the said slidable member, said leverage devices acting to bear upon the inlet valve and hold it open on starting, but to release the valve when the compressor has attained sufficient speed to cause the weights and sildable member to actuate the leverage devices, and a spring adjustable along the length of the leverage devices and adapted to be compressed as the leverage devices are rocked.

In a compressor, the combination of a cylinder, piston and crank shaft, an inlet valve for the cylinder, centrifugal weights pivotally mounted on one end of the crank shaft, a slidable member actuated axially and outwardly from the crank shaft as the weights fly outwardly, a pivoted lever extending from a point near the inlet valve to a point opposite the weights, a shield on said lever extending over the. weights and adapted to. be engaged by said slidable member, means connected to the lever and bearing on the inlet valve for holding the inlet valve open FREDERICK W. PARSONS. 

